Microscopic origins of metastable effects in a-Si:H and deep defect characterization in a-Si,Ge:H alloys. Annual subcontract report, 1 February 1991--31 January 1992
- Oregon Univ., Eugene, OR (United States)
This report describes works to use transient photocapacitance and photocurrent measurements to determine the deep defect distribution and processes in low-band-gap a-Si,Ge:H alloys. Samples for these studies were produced by the photochemical vapor deposition (photo-CVD) growth method and were obtained through a collaboration with researchers at the University of Delaware. This report discusses how a detailed comparison between the photocapacitance and photocurrent spectra can be used to separately examine the majority and minority carrier processes. The results are as follows: (1) The midgap defect densities in the alloy regime near 1.3 eV can be as low as 5 {times} 10{sup 16} cm{sup {minus}3} in such photo-CVD samples. (2) There exists a second defect band roughly 0.4 eV below E{sub c} of a similar magnitude to the midgap defect density that exhibits significant lattice relaxation behavior in its electron trapping dynamics. (3) The hole {mu}{tau} products determined for the lowest defect sample are roughly 5 {times} 10{sup {minus}10} cm{sup 2}/V, comparable with the highest hole {mu}{tau} products reported in sandwich geometry measurements for alloys in this composition range. (4) The hole {mu}{tau} is found to be roughly inversely proportional to the midgap defect density for the samples studied. This is consistent with the fact that the effective minority carrier lifetime for such measurements is limited by the deep state trapping time.
- Research Organization:
- National Renewable Energy Lab., Golden, CO (United States); Oregon Univ., Eugene, OR (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC02-83CH10093
- OSTI ID:
- 10170190
- Report Number(s):
- NREL/TP--451-4938; ON: DE92010588
- Country of Publication:
- United States
- Language:
- English
Similar Records
Microscopic Origins of Metastable Effects in a-Si:H and Deep Defect Characterization in a-Si,Ge:H Alloys, Annual Subcontract Report, 1 February 1991 - 31 January 1992
Microscopic Origins of Metastable Effects in a-Si:H and Deep Defect Characterization in a-Si,Ge:H Alloys, Annual Subcontract Report, 1 February 1992 - 31 January 1993
Microscopic Origins of Metastable Effects in a-Si:H and Deep Defect Characterization in a-Si,Ge:H Alloys: Final Subcontract Report, 1 February 1991 - 31 January 1994
Technical Report
·
Tue Jun 30 20:00:00 EDT 1992
·
OSTI ID:7233282
Microscopic Origins of Metastable Effects in a-Si:H and Deep Defect Characterization in a-Si,Ge:H Alloys, Annual Subcontract Report, 1 February 1992 - 31 January 1993
Technical Report
·
Sat Jul 31 20:00:00 EDT 1993
·
OSTI ID:10180625
Microscopic Origins of Metastable Effects in a-Si:H and Deep Defect Characterization in a-Si,Ge:H Alloys: Final Subcontract Report, 1 February 1991 - 31 January 1994
Technical Report
·
Wed Aug 31 20:00:00 EDT 1994
·
OSTI ID:10183684
Related Subjects
14 SOLAR ENERGY
140501
36 MATERIALS SCIENCE
360602
360606
AMORPHOUS STATE
CAPACITANCE
CHEMICAL VAPOR DEPOSITION
CRYSTAL DEFECTS
GERMANIUM ALLOYS
METASTABLE STATES
PHOTOCONDUCTIVITY
PHOTOCURRENTS
PHOTOVOLTAIC CONVERSION
PHYSICAL PROPERTIES
PROGRESS REPORT
SEMICONDUCTOR JUNCTIONS
SEMICONDUCTOR MATERIALS
SILICON
SILICON SOLAR CELLS
SOLAR CELLS
STRUCTURE AND PHASE STUDIES
140501
36 MATERIALS SCIENCE
360602
360606
AMORPHOUS STATE
CAPACITANCE
CHEMICAL VAPOR DEPOSITION
CRYSTAL DEFECTS
GERMANIUM ALLOYS
METASTABLE STATES
PHOTOCONDUCTIVITY
PHOTOCURRENTS
PHOTOVOLTAIC CONVERSION
PHYSICAL PROPERTIES
PROGRESS REPORT
SEMICONDUCTOR JUNCTIONS
SEMICONDUCTOR MATERIALS
SILICON
SILICON SOLAR CELLS
SOLAR CELLS
STRUCTURE AND PHASE STUDIES